Heading to the beach in the morning? You may want to avoid a late-night snack the evening before you go.
Researchers studying mice found that eating at odd times disrupt what they call the "biological clock of the skin." It affects the daytime strength of an enzyme that protects the skin against the sun's dangerous ultraviolet radiation.
Although the findings are preliminary since the study was only performed in rodents, the results suggest that if you eat late at night, you may be more susceptible to sunburn and long-term sun-related skin issues such as skin aging and skin cancer, said study co-author Dr. Joseph S. Takahashi, Chairman of Neuroscience at UT Southwestern Medical Center’s Peter O’Donnell Jr. Brain Institute.
“This finding is surprising. I did not think the skin was paying attention to when we are eating,” said Takahashi in a statement.
For the study, some mice were given food only during the day (an abnormal feeding schedule for the nocturnal animals) and others ate at their usual evening times.
The mice who ate on an abnormal schedule had more skin damage when they were exposed to ultraviolet B (UVB) light during the day than during the night. According to the researchers, this damage happened partially because xeroderma pigmentosum group A (XPA) — an enzyme that works to repair UV-damaged skin — shifted its cycle in order to be less active during the day.
Mice that were fed during their normal eating times showed no changes in the enzyme and were less susceptible to UV damage.
“It is likely that if you have a normal eating schedule, then you will be better protected from UV during the daytime,” said Takahashi. “If you have an abnormal eating schedule, that could cause a harmful shift in your skin clock, like it did in the mouse.”
Researchers said the study, which was published in the journal Cell Reports, is a first step. But more work needs to be done to understand the connection between eating times and UV damage in humans.
“It’s hard to translate these findings to humans at this point,” said Dr. Bogi Andersen, professor of biological chemistry at the University of California, Irvine, who led the study. “But it’s fascinating to me that the skin would be sensitive to the timing of food intake.”